<!DOCTYPE HTML>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    <title>计时器</title>
    <script type="text/javascript">
        var inter = setInterval("clock()",100);
        function clock(){
            var time=new Date();
            document.getElementById("clock").value = time;
        }

    </script>
</head>
<body>
<form>
    <input type="text" id="clock" size="50"  />
    <input type="button" value="Stop"  onclick="clearInterval(inter)"/>
</form>
</body>
</html>